SPR: Stack-to-Pot Ratio

Stack-to-pot ratio, commonly known as SPR, is a fundamental poker concept every winning player needs to understand. This week, James ‘SplitSuit’ Sweeney is on the podcast to explain why the size of the effective stack relative to the size of the pot demands your full attention.

If you’re new to SPR, this episode is going to transform your game. If you’re already familiar, there’s value for you here in refreshing your understanding, because SPR is something you will use in basically every pot you play.

Zac: Okay, so SPR as I said in the intro is something that really every poker player needs to have a working knowledge of, and for a lot of players do have that working knowledge, but for those who don’t, those who this is a new concept for them, can you give us a quick, brief overview on what SPR is exactly?

James: Sure, so SPR stands for stack to pot ratio, this was made most famous, I think actually really introduced to everybody in the book Professional No-Limit Hold ‘Em and this has been something that I have spent a lot of time thinking about, a lot of time kind of crafting preflop and flop strategy around and ultimately SPR is a very, very simple thing. The formula is simple effective stock size divided by pot size. Very clear example, if say you have $150 effective stack on a flop, in the pot is $50 right that moment, $150 divided by $50 equals three, so you would have a 3 SPR pot. At the end of the day, that’s really what SPR is, SPR as a formula is very simple but SPR as a concept is even more important. Essentially what it is, is it guides you on how committed or non committed you are to a pot.

Now, a couple caveats about SPR. SPR is something that you use on the flop. You can also use it preflop when you’re thinking about okay, where is the SPR going to be on the flop, but you don’t re-calculate on turns or rivers and it’s only a metric that you use, again on the flop before any betting that is done. Once the flop is dealt out, what is the pot right that moment? That’s the pot size used and then again, SPR is effective stack size divided by pot size and you calculate it from there. A small SPR simply means that you are more automatically committed to the pot. A large SPR means that you are not as automatically committed to the pot and to the point where you could not have to be committed at all. For example, you get into a pot and it’s 10 SPR, so the pot’s $50 and you have $500 behind, so again, 10 SPR. There’s no reason for you to feel like you’re automatically committed to that situation.

Now of course you could decide okay, I do want to get my stack involved but you don’t have to, you’re not automatically committed. But in that same situation, again if it’s a $50 pot but you only have $100 left or you only have $50 effective left, again that SPR starts dropping down to one or two, now all of a sudden you’re getting very very close to commitment and most of the time you should be sticking it in when you have anything even slightly decent.

Zac: I’ve been studying SPR a lot recently and I tried to pick one area of it to focus on, and as you just said that reaching that two SPR seems to be a key part of this whole idea is you always want to be aware when you reach that red line because at that point you’re really playing for stacks and not just your own stack but perhaps for someone else, your opponent is playing for their stack too.

James: Yeah, exactly. SPR is something that you have to be very, very cognizant of and a lot of people trend to be reactive to SPR, they do whatever they want to do preflop and then they find themself in this flop situation like oh crap, I happen to have a small SPR. But SPR is something that you really want to be proactive on. You want to be thinking about it from preflop, okay what is the SPR going to be if we do in fact go to the flop, is that going to be good or bad for my hand? How am I going to play if I hit versus miss versus catch and draw… and if you can be proactive with that thought process, your preflop play gets infinitely easier and then also your flop decisions just become really, really automatic because you already know okay, this is the spot where I am going to be sticking it in or this is the spot where I don’t have to be sticking it in, I’ll create a strategy from there.

Zac: SPR and bet sizing go hand in hand and that’s where its really helped me with bet sizing because assuming you have some standard bet sizing going on, your SPR calculations become kind of predictable where you can think about “well if I get raised here, then my SPR is going to go to this range and so on” so that helps you kind of simplify things, right?

James: To an extent, now if you’re kind of brand new to it and you’ve never really about what your preflop bet sizing really does to the flop size by the time you actually get there, this would probably be a good time to spend a little bit of time doing that. Ask yourself “okay if I raised to my normal size in my game and I get one caller, what’s my default SPR going to be?” Based upon again, how deep your game runs, what you typically buy in for, that sort of thing. Then you should also do the same thing for “OK, if I raise my standard size in my game and I end up getting two colors, what is the SPR going to be on the flop.” Do the same thing for if you get multiple colors, if it’s a three bet pot, if it’s a three bets where you happen to squeeze instead of just a default three bet. Kind of go forward from there and really think about what are the typical SPR’s you find yourself in.

Typically, in some SPR’s you’re gonna find yourself very deep and nowhere close to committed unless you’re playing against a very short stacked opponent. But when you’re playing in three bet pots, four bet pots especially, it’s very, very common, especially in live games where the pot size is so much larger and then online it’s very easy to find yourself in these kind of awkward SPRs around three and four, but also you find yourself in a lot of small SPR pots as well. You have to have that plan and you have to have that pre-flop process early on.

Zac: Now that’s really good to hear because that’s exactly what I’ve doing to study it. The thing I love about that study technique is you can do it while you’re doing the dishes or you’re doing laundry, you can just in your head game out these typical scenarios that happen in your game that you play and then think about okay, well that puts me in this kind of spot, what do I do there. What are some of the other ways that we can study SPR or some of the other skills that we should be studying in addition to SPR once we kind of are gaming through those SPR scenarios?

James: When it comes to working with SPR off table, definitely getting familiar with your fold equity calculator is gonna be very important because a lot of people it’s just not simply intuitive to them that when they say, find themselves in a 1.5 SPR pot on the flop, they have ace king and happens to win the flop, it’s not necessarily intuitive to them that they should be looking to commit in that situation with just ace high. But when you’ve run this situation out enough of the time, when you’ve done that fold equity analysis flops and you’re able to say okay, this is a stop where my opponent’s definitely folding a lot and it’s a small SPR pot and they’re gonna be the ones making a larger mistake here, I should be sticking it in with ace high, then all of a sudden you get much more familiar and comfortable with it. Again, a fold equity calculator definitely every helpful and an EV spreadsheet, we have one on Red Chip, definitely suggest that and we’ll leave a link for that in the show notes for this for sure. It’s just one of those things where it’s very, very mathematical in the small SPR pots.

That being said, we’re talking about small SPR pots here, but what about medium SPR pots? What about large SPR pots? Well again, in those situations you’re usually not default committed so things like ace high don’t become automatic stalk offs, like they might be in a one SPR pot. That being said, once it comes into a deep SPR pot, you’re away from commitment, well at that point it’s really just your post flop skill sets gotta come in and you say okay, well I’m not automatically committed here, I’m just gonna do what I normally do and at that point you kind of ignore SPR because once it gets really deep, higher than 6 especially, you just kinda don’t worry about it too much. Again, you’re nowhere near auto commitment.

Zac: That’s why, thinking about that SPR of two as sort of a fulcrum seems to be a really useful starting point and also in these low stakes cash games which I know a lot of our listeners play, you’re often facing opponents who have effective stacks much smaller than yours and therefore are dealing with much smaller SPR’s than would actually be resulting from your stack size, right?

James: That’s exactly right, and again because in live games you typically see the larger open size or the larger three bet size than you would versus online, it’s easy to see how that SPR can get shrunk very, very quickly and especially in three bet pots or squeeze pots, it’s not uncommon to find SPR’s that are between one and two or one and two and a half, and again you have to have those automatically ingrained. Once you do, then it becomes easier to say okay, how should I make preflop adjustments if any, again, if I’m gonna constantly be creating these small SPR pots where I’m automatically committed, do I really want to be doing this light three that would jack someone suited. Creating a small SPR pot rejects someone who doesn’t play particularly well. Again, it helps you kind of craft your preflop brain just as well when you’re being proactive and thinking about what that SPR is gonna be.

Zac: Gotcha. I’m really into getting into a hand history right here, and we found one in the forum. Before I ask you that though, one more question about actually applying these SPR skills at the table and these low stakes cash games. We noticed that a lot players are playing without SPR awareness, they’re making bets that commit their entire stack when really they should be shoving those types of things. How do we exploit those players who we can identify as people who don’t have that SPR awareness?

James: So the way that you identify people that don’t really have it is they find themselves in a lot of small to medium SPR pots, and they typically fold far too often. If you find someone who is just constantly finding themselves in a one or two SPR pot on the flop, and they’re constantly relinquishing, typically they have no SPR awareness, and they’re blatantly not crafting strategy or plans based upon what that SPR is gonna be. You can find situations where they’re folding far too often, which actually allows you to do some pretty creative things. Now you have to be very, very aware, you have to pay a lot of attention to spot that, but it’s definitely something that can be very, very useful and help you craft better preflop lines.

Zac: Right on, okay. Let’s get started with this hand history that we pulled out of the forum, and this is a 2/5 live hand. Why don’t you set up the hand and kinda talk about some of the SPR considerations that we have when we’re thinking about this hand strategically.

James: Okay, so we’re gonna do our best to make this as easy to follow as possible. I know hand histories can be a little difficult on the podcast, but we’ll do our best. We’re playing 2/5 live and it’s $480 effective to start the hand. There are two limpers, one for five, limp for five. Late position raises to $25 total, hero decides to 3-bet from the cut off to $85 total with A2s. Then it folds back to middle position who calls. At this point we’re just gonna round it up and this is something that even when I’m in real time, I mean you can get nitty gritty and granular to the dollar, but typically I just round things just so I’m close enough. There’s not a huge functional difference between 2.2 SPR and 2.4 SPR. As long as you’re in the ballpark, you’re pretty close, you’re fine, you’re good to go.

In this situation we go to the flop and remember, because we three bet to $85 got called, there were some lumpers, there was the blinds, we’re just gonna round the pot size on the flop to $200 and because we started with $480 effective, we’d say there’s roughly $400 behind. Again, SPR, effective stack size divided by pot size, $400 divided by two hundred equals 2 SPR. As a pure default, two SPR and below, I’m typically gonna be sticking it in very, very happy with things like top pair, things like good solid draws, over pairs, all that kind of stuff. Now the smaller it gets the more often I’m gonna stick it in with even ace high and stuff like that, but that’s not really what we’re gonna cover on this hand exactly.

So again, two SPR going into the flop, we have ace, deuce of clubs, flop comes ace, king, six, rainbow, no clubs present. Middle position decides to check, hero decides to bet for a hundred, so half pots and middle position rips it in, so it’s $300 more for hero to call. At first glance, hero is getting 2.3 to 1 on pot odds, what are your immediate thoughts if any on this hand?

Zac: Oh boy you’re putting me on the spot?

James: Yeah, I’m gonna put you on the spot this time, you always put me on the spot when it comes to hand analysis.

Zac: And here I am thinking about the next question. Well, let’s see here. We’ve got MP is ripping it in for 300 more for us to call and the pot is going to be what here … we made it-

James: Just break it down, we’ll break it down simply. We have let’s just say two SPR exactly, we flop top pair, no kicker, ace, king, six, we have ace, deuce of clubs and at this point we’re getting 2.3 to 1 on the call. Your immediate thought right there, top pair, two SPR is it to get it in or is it not to get it in?

Zac: Hm, I mean it’s a tough one because I’m trying to do the hand reading here and trying to put them on a range, first of all what would they call over A’s preflop. They raised and called a free bet rather so they must have a pretty decent holding, I would put better aces than ours in their holding, I would put hands like king, queen, maybe even queen jack so every once in a while they come through with the draw, but it doesn’t look like a very draw heavy board, so I would kind of give them credit for a better ace a lot of the time. I’m not sure if that’s what I should be doing but-

James: And you’re not alone there.

Zac: Right.

James: Yeah, you’re definitely not alone. I think a lot of people would look at this and say well, he could have ace jack, he could have ace queen that crushes my ace deuce and thus they just get rid of the hand. But going back, we started this with two SPR. As a pure default two SPR and below, top pair I’m definitely going to be getting it in. In this situation a lot of people say well I’m getting 2.3 to 1, I don’t need to be right that often and you’re totally right. Obviously when you’re behind something like ace queen you have some equity which is all well and good. But the way that I look at it is this, if I were to fold here, I better be very, very, very, very certain the middle position has no air, no king X, no draws, no nothing like that. The fact of the matter is that more often than not, there are gonna be some combinations of some second best up. Doesn’t matter what it is, doesn’t matter if it’s king queen, king jack, king five suited, six seven of hearts, it doesn’t matter in this scenario.

There can be some second bests and if there can be, often times it’s going be to enough to justify getting it in. Again, it’s a small SPR pot. If you’re making constant over fold mistakes in small SPR pots, you are making some very, very big errors and often times making some assumptions that are probably bordering on way too nitty. Again, I got here with two SPR, I flop top pair so all my kind of commitment necessary thresholds are met and as such I’m gonna be getting it in here. Am I super, super stoked about it? No. I’m gonna run into ace queen sometimes, sometimes ace king, sometimes ace jack, those kind of things, but ultimately I think there can be enough second best combos to justify given the way this all worked out.

Some of the major things that kind of come up from a hand like this again is, was the preflop three bet really good thinking about how many immediate folds you were getting, because if you don’t get those immediate folds you know you’re playing two SPR pots. Then thinking about what’s the plan for c-betting here, what’s the plan for commitment, right? The smaller that SPR is, the more you need to be prepared right that moment for okay, what if the fireworks go off because the smaller the SPR, the more often those fireworks are gonna go off as is and you have to know what you’re gonna do in advance.

Zac: Right. I’m kind of applying the typical player in a one, two game that I would apply to this and thinking no one’s going to shove like that without a made hand, but when I look back at the preflop action, I wonder if we need to three bet here with ace deuce suited when better aces are a huge part of MP’s range when they raise.

James: I mean we don’t want to go so black and white as that because if we were to say that then we would never three bet really anything light because well if they continue against our three bet they’re gonna have a stronger range. That’s always the case whenever we’re bluffing, be it ace deuce, be it nine seven suited, doesn’t matter what it is. It’s more about how many folds we were getting preflop, was that good or bad and what was gonna be our flop plan again when that two SPR pot rolled up. We have to know these kind of things. Again, these numbers aren’t super uncommon. We started with roughly $100 big blinds preflop, it’s a normal three bet pot, and in this situation we find ourselves two SPR on the flop.

Well, you need to know this stuff, this needs to be like on the back of your hand. A lot of people will use the argument of well I think my opponent just has ace queen here. I don’t know, maybe, but I’ve seen people show up with jack ten suited here. I’ve seen people show up with king ten suited and they just don’t know what else to do with it. When you can start adding in those second best combos, you realize that if you start over folding here, you could really start making some huge mistakes and leaving heaps of money on the table.

Zac: What you say about once we three bet and get called, we’re shipping it in on this flop all the time, that makes a whole lot of sense from an SPR consideration and what we would be thinking about preflop is when we make this bet to 85, we’re basically shipping most flops, right, where the plan is for this person to check to us and for us to ship, right?

James: Okay so you raise a really fair point that a lot of people bring it up and I need to kind of fill this in. Just because we’re in a committed SPR situation, does not mean that we need to ship it. I say that for two major reasons. One in this situation, if we were to just open ship after MP checks the flop, we’d be shoving 400 into 200. Well that’s not really super great, and we can do other things that don’t involve just shoving for no reason, so the smaller that SPR is the more reasonable it is, especially when it’s like 1 or .8 SPR pot, something like that. But especially when you get into like 1.5, 2X SPR, you’re not in automatically have to ship. Again, having a commitment mindset doesn’t mean that your only move is to shove right that moment, you can commit in lots of different ways.

Which brings me to my second point, the values side of the spectrum. Lets just say that we had aces here, right, again, ace king six rainbow, board you have the nuts. In that situation, again, why would you just ship? Again, you could check but again, you still have that commitment mindset because it’s a committed SPR so your plan could be to commit it on the turn, commit it on the river. You’re just overall thought process is to say okay, I’m not gonna fold in this hand, that’s really where the commitment is coming from.

Zac: And player type matters here too because I imagine some players who are when we bet 100, shipping it against us, could be doing that with any number of hands trying to put pressure on us assuming that if we don’t hold the ace then we are folding out here. Some other players who are much more passive might call the bet or might even fold with a king type of hand, right?

James: Well that’s exactly my point from earlier is, you better be damn certain if you’re in a full top pair in a two SPR pod, like damn certain. A lot of people will make the excuse of well, I don’t know I think he’s nitty. But they’re just making that assumption because they play a little too nitty. You need to be damn certain that they are not gonna show up with any second best hands anywhere near enough of the time. More often than not, especially in a lot games where people will get tilted for no reason, maybe they have to go home in a couple of minutes, you don’t fully realize that but they’re just ready to gamble. There are plenty of situations and in most of them, people are far wider than you give them credit for especially in a live environment.

Again, over folding can only be done if you are damn certain that, that’s exploiting the fact that they have no bluffs or so few bluffs in their range that you can get away with over folding to exploit them. More often than not you leave yourself open to getting exploited if you’re over folding these small, committed SPR’s.

Zac: Okay, well I think I grasped the concepts a little bit better here. It’s still so very complex though because every decision you make reverberates through the entire hand, and I guess it’s fun to game these things through and think about the different considerations, but it does seem to all start with hand reading and then you’re kind of comparing stacks. Is that the kind of thought process that you’re advocating for here?

James: Yeah, I mean small SPR pots, let’s just be honest, they’re very, very mathematical, they’re very, very technical. At the end of the day, they’re actually pretty damn easy. It’s just simple math, am I committed, am I not. What constitutes commitment, what SPR constitutes top pair being awesome, what SPR constitutes ace king high being good enough to ship it, that sort of stuff. Honestly, if you mess around with this stuff for let’s call it 40 minutes, you’ll get a really, really good feel for this stuff. It’s not overly complex. Again in most situations, you’re not gonna have an SPR that’s so small that you’re automatically committed unless again, you’re in a three bet, four bet, five bet pots where typically you’re gonna find that smaller SPR.

More often than not the SPR is just gonna be large enough that you get to play poker, you’re not automatically committed unless you want to be, go forward from there. In these super small SPR pots, some technical prowess is going to be very, very beneficial.

Zac: Well that’s awesome, it’s always great to go over hand history with you and I want to thank Sully O, Sully with three O’s in front of it, I don’t know if that’s Sullyooo, but he or she was the person to submit that hand and through our listeners, go to the forum, leave your hand histories in there, you’re gonna get great advice from us and sometimes even a coach. We gotta do more of these hand histories on the podcast I think because I think that makes sense, right?

James: Fingers crossed, I’m looking forward to feedback and seeing if people enjoyed it, need us to slow it down, don’t want hand histories in the future, or want heaps more, just let us know, we’re totally open to that kind of feedback.

Zac: Awesome. Yeah definitely let us know, and until the next hand history, thanks again for doing the podcast and I hoped that we can do another one sometime real soon.

James: Indeed, I’m sure we will, thanks for having me Zac, take care and we’ll chit chat soon.